A tin fluoride-free, efficient and durable tin-lead perovskite solar cell.
basic_science · Level V
Where this comes from
- Record sourced from PubMed, PMID 41526334.
- Also identified by DOI 10.1038/s41467-025-65445-0 and PMC identifier 12796181.
- Licence recorded as CC BY.
- The licence permits redistribution, so the abstract is shown in full and the full text is available from the publisher.
Abstract
The photo-thermal stability of tin-lead perovskite solar cells remains a major challenge. SnF<sub>2</sub> is commonly used to inhibit Sn<sup>2+</sup> oxidation and reduce hole density, however, the stability of devices remains poor. Here, we found that the poor stability partially results from an adverse effect of SnF<sub>2</sub>, which reacts with formamidine iodide during photo-thermal treatments. This reaction leads to degradation of perovskite and release of hydrofluoric acid, which corrodes electrodes. To address this issue, we develop a strategy that combines lead powder in precursor with PbF<sub>2</sub> post-treatment, replacing the role of SnF<sub>2</sub> as in film formation and surface defect passivation, respectively. The d-electron polarization in Pb<sup>2+</sup> strengthens its bond with F<sup>⁻</sup>, making it react inert to perovskite. In this work, the efficiency of SnF<sub>2</sub>-free devices increases from 16.43% to 24.07%. The cells retain 60% of their initial efficiency after 550 hours operating at 85 °C under maximum power point.